A Study Of Crashworthiness Of Passenger Car In Side Impact Based On The Force And Energy Transfer Path

The huge impact load will be applied on the vehicle in a short time in side impactand there may be a big injury risk on the passengers if the collision energy can not betransmitted to other parts quickly because of the unreasonable body structures. Thecollision energy can be distributed to the body with the reasonable load transfer pathand the crash performance of the vehicle will be improved significantly. So how totransmit the impact load to other parts fast and effectively have a major part to play inimproving the crashworthiness and reducing the injury risk of occupants.The aim of the present thesis is to design a reasonable load transfer path byimproving the structure of the vehicle body and optimizing the critical components.Comparison of studies on the difference of the injury of the dummy and the intrusionof front and rear door, hoping to not only reduce the injury risk of the front-rowpassengers but also to effective protection of rear-row occupants.Firstly, the paper summarizes the traffic accidents type and the developmentoutline of automobile passive safety in recently years. In addition, the paper comparesthe different collision regulations and research methods of side impact at home andabroad. After that, it introduces the basic theory of the finite element. According toECE R95, the FE model of vehicle and MDB are all established and validated bycomparing the simulation results and test results.Because of the unreasonable load transfer path on the floor, the energy can not betransmitted to the parts of another side of the body, so the collision energy isaccumulated at the bottom of the B pillar. All of these result in the large deformationsof floor and outer frank of the car. For this reason, in order to prevent local largedeformations and make the collision energy can be transmitted to other partseffectively, the rear installation position has been changed and the joint strength ofbody has been improved.Based on the analysis of the location of MDB in ECE R95, a conclusion is drawn:there is a big difference between the load carried by front door and rear door. The loadcarried by front door is much larger than rear door, so there is much greater injury riskto front row passengers than to rear row passengers. The injury risk of front and rearpassengers will be reduced by a reasonable strength matching of front and rear door.The results of this study indicate that the intrusion of B pillar has been reducedsignificantly, and the pattern of deformation of B pillar has been improvedsubstantially. The large area fold deformation of floor has been eliminated and the intrusion of seat frame also has been reduced. The results of PSM analysis indicate thatall of these structure optimizations have a great effect on the reduction of head injuryand thoracic injury. The intrusion and velocity of body are reduced significantly withreasonable strength matching of rear and front door and aim of occupant protection hasbeen reached.